linq c＃按月份和年份范围分组

I have a list of records with dates. I want to group this list by month and year, so for example I could have dates that span a range from October 2012 until march 2013, then april 2013 until september 2013 and then October 2013 until march 2014 and finally april 2014 until sept 2014I have a list of records with dates. I want to